Electrolytic alkali halogen cell



Nov. l4, 1947. K. E. STUART 2,430,374 ELEC'HOLY'IIC ALKALI HALOGEN CELLFiled Aug. 25, 1945 2 Sheets-Sheet l INVENTOR Nov. 4, 41947. K.\ E.STUART l y ELECTROLYTIC ALKALI HALOGEN CELL Filed Aug, 25, 1945 2Sheets-Sheet 2 Patented Nov. 4, 1947 ELECTROLYTIC HALO GEN CELL 4Kenneth E. stuaiumagnra; FaiisN; Y., assigner `to Hooker` yEleotrochemical Company, Niagara Falls, Nail., acorporation of New YorkjFAppl-icatioxrAligllst^23, 1945,' 'Serial'No:612,1 6-1Y My inventionrelates more particularly toan` improvement upon the cell disclosed inPatent No. 1,866,065, granted to me July 5, 1932. O-ne object of myinvention is to provide a non-conducting member separating and formingliquid tight joints with the outer metal retaining Wall structure of thecathode assembly and the at metal plate to whichthe anodic electrodesare conductively affixed, when this plate constitutes a closure memberof the cell. Another object of my invention is to protect this plateagainst electrolysisv which would otherwise result from aocdental minorleaks past said joints, when the plate constitutes the bottom closuremember of the cell.

Referring to the drawings:

Fig. 1 is a sectional elevation through a cell of the type disclosed inthe patent referred to, showing the construction of the cathode assemblyand bottom closure member, and of the non-conducting separating member.

Fig. 2 is a sectional detail of a portion of cathodic outer metalretaining wall, the bottom olosure member and the non-conducting member,to an enlarged scale.

Fig. 3 is a plan view of the non-conducting member by itself, to areduced scale.

Fig. 4 is a side elevation of the non-conducting member by itself,partly in section, to the scale of Fig. 3.

Fig. 5 is an end elevation of the non-conducting member by itself,partly in section, to the same scale.

Fig, 6 is a sectional detail of a portion of the oathodic outer metalretaining wall, bottom clo- Sure member and non-conducting memberseparating the 'tv/0,. all of Ymodified. constructionyto the scale ofFig. 2. L

' Fig'. 7 is a plan'viewof a corner of the nonconductingmemberconstructed in accordance with the detail of Fig.l 6, but to the scaleof Figs. 3 to 5. v l

Fig. 8is a'sectional detail of the bottomgclosure member andnon-conducting member` illustrated in Fig. 6, but adapted to aV modiedtype of cathodic outer metal retaining wall, f

VReferring to Figs. 1 to 5:

Element l is a gas collecting cover member of halogen-resistant,non-conducting material, such as concrete, provided with exit 25 for thehalogen gas. Element 2 is the cathode assembly, comprising outerretaining wall 3, provided with exit 26 for hydrogen and Aeiiluent pipe21 for caustic alkali solution, foraminous cathodc electrodes, #adaptedtobe covered with asbestos diaphragm forms the bottom member of thecell, the 4lower endsui electrodes 5 being preferably embedded irisl'absof lead "I, flgbondedto plate 6. Plate 6 fened by ribs `29, which inturn rest upon *MS-39.5" 1 11] -f.. y .n

Brine `is* supplied Ttothe inner compartment of the "cell, "to serveI agelectrolyte therein, by means bffa'tubular'lcontrolling device, notshown, in ac meeneemt-'nui js.-Paten1;No. 2,183,299, .gratifiedto"MmeDecember' l?, Element `28 is /afltrolytelevelindicating device, ofthetype `in which'tle pressure built up by Ygas; inthis*.oaselchlineftrapped-in a chamber having an opfendofvnw'ardlydirected mouth, is indicated by'fa manometer, Ythusgiving a measure ofthe sbmergence of themouth.

,Dirct""lectrie current is fsupplied to the cell ronafsurce notsho-Wn,through bus bars 25, 25. L Re'sting'fupon plate 16 and conforming withthe xterior"shape` of` thecell, is a flat irameAS, of non-conductingmaterial, such as slate, concrete, ,affcjoril'position,,of` asbestosYber and cement, or otherequivalentmateriah but inthe drawings.sllwnasponstructed of wood. Frame 8 supports Qatliode assemblyzfandconstitutes the non-conducting member referred to above. ',Wall is.outwardly ilanged'at 9 and lil, as will be .seen in Figs. ,l vand 2,and the joint between iiange ,LB and frameB is rendered liquid tight by?`,flexible `gasket l l, of foircular cross section, whiclfirlshall referto as `a rope-type gasket, Iinaceor dan'ce".with Patent No. 2,208,778,granted teme July23 1949. .Gasket Il` isL housed in a groove l2 formedin the upper-surface of` frame 8, butpresents .a rounded surface toflange- Il), whichsurface ,becomes flattenedby pressure ,of tnedlange,,as illustrated in` the gures. This type .of gasket requires `that theframe oe `Well fllleted at its, corners, as shown in Fig. 3. In theconstruction of Figs. .Land 2,in which the iriange f Wall -3 is.outwardly ydirected, frame in may ex tend-to the outer edgeof the`ilange, in which case frame Bis preferably formed of four side piecesand four cornerbleplgs i3, as clearly indicated in f3, the.-sidefpieeesand corner blocks beingfsecuredQtogether by straps `ifi bolts-.15. Thejoint betweenlframe 3 and plate 6 is rendered liquid tightby gasket i6.,which is similar to gasket il. and; similariymoused n in4 groove` Il,formed in the 4lower,surfage ojfranie' 8. lFrame is, how- 3 ever,secured to plate Ei by bolts I8, and adapted to remain in position whencover I and cathode assembly 2 are removed.

Lead slabs 1, in which the lower ends of anodic electrodes 5 areembedded, are formed by pouring molten lead into the pans `formed byplate 6 and ns I9. The space between electrodes 5, lead slabs '1, finsI9, plate 6, gasket I6 and frame 8 is sealed by pouring in moltenbitumen, forming layer 28, which extends between electrodes 5 andcompletely covers and protects the metallic surfaces associated with theanode assembly.`

Layer 20 is preferably carried upward around its edges so as to coverthe upper inner edge of frame 8 and over the upper surface of frame 8 asfar as gasket I I. Frame 8 may have been previously renderedwater-resistant by impregnation with a water repellent oil, such aslinseed oil or a hydrocarbon drying oil; but in any case it is desirableto protect frame 8 as far as possible by carrying layer 2lover it togasket II`. The material of layer 20 is plastic, even when cold, andwill not prevent flange I from seating itself rmly upon gasket I I.

In Fig. 6 there is illustrated a modified structure in which the flanges2| of cathodic retaining wall 3 are inwardly directed. In this case theanges may be integral with the wall as before, but in the figure areshown as separate pieces welded thereto. One object of this constructionis to economize floor space occupied by the cell. A comparison of Figs.2 and 6 will show at a glance that by the construction of Fig. 6 thereis a considerable reduction in the outer dimensions of the cell. This isaccomplished, however, at the expense of the lateral space available forthe sides of the frame, which is indicated at 22, and which in Fig. 6constitutes the non-conducting member. Owing to the reduced width offrame 22 as compared with frame 8, the corners may be formed by sawing,steaming and bending, as illustrated in Fig. 7. In this case, sincethere is no space outside gasket I8 for the holding down bolts, a lagscrew 23 is used, and this is placed inside of gasket I6.

In Fig. 6 there is also illustrated another feature of considerableimportance, namely drip rim 24, formed along the outer face of frame 22and extending downwardly around, outside of and below the edge of plate6, as clearly illustrated in the figure. The purpose of drip rim 24 isas follows: In an alkali halogen cell, the metal parts of the cathodeassembly, if of iron, are unaffected by electrolysis. However, plate 6,and all metal parts associated with it, are anodic. There is no knownmetal but platinum which will withstand nascent halogens. If iron beexposed to anodic conditions in an electrolytic chlorine cell, thechlorine combines with it as fast as withdrawn from the electrolyte. Nochlorine whatsoever is liberated upon the iron surface, but all thechlorine appears as ferric chloride. Since this is Very soluble,A underthese conditions the iron itself melts away almost as if it were itselfsoluble. Any accidental minor leak past gaskets II or I6 will thereforehave a serious destructive effect upon the edge of plate 6, and in avery short time. Leakage past gasket I6 need never occur if bolts 23 areproperly drawn down, and if it should start, can be quickly stopped.Leakage past gasket I I is, however, not always so easily prevented.Nevertheless, by the construction of Fig. 6, electrolyte leaking pastgasket I I ows over the outer surface of frame 22 and runs 01T from driprim 24, without any possibility of its contacting the edge of plate 6.This plate is therefore completely protected against the destructiveeffect of electroylsis.

In the modification illustrated in Fig. 8, the

cathodic outer retaining wall 3| is flangeless, as

more fully described and illustrated in co-pending application SerialNo. 597,259, led June 2, 1945. The upper and lower rims 34 and 35 ofwall 3| constitute flat gasket bearing surfaces.

1o The lower rim 34 of wall 3| rests upon gasket 32,

which in this case is a fiat sheet of resilient material covering theupper bearing surface of frame 22. Similarly, the weight of top member Iis supported by the upper rim 35 of wall 3|, with flat sheet gasket 33between.

This application is a continuation-impart of application Serial No.438,725, led April 13, 1942, now abandoned.

I claim as my invention:

l. In an electrolytic alkali chlorine cell comprising a cathode assemblyincluding a foraminous structure and cathode electrodes housed in anupright liquid-retaining wall provided with a normally horizontal fiatgasket bearing surface 25 all around its lower edge, and an anodeassembly co-operative with said cathode assembly including uprightanodic electrodes having their lower ends embedded in a slab of lowmelting metal; the improved support for said cathode and anodeassemblies and bottom closure for said retaining wall comprising a atmetal plate extending beneath said retaining wall completely across fromside to side thereof and conductively affixed to said slab; a flat,four-sided open frame of impervious electrically non-conducting materialintervening between said plate and the cathode assembly conforming withsaid gasket bearing surface in plan View, and having upper and lowerboundary surfaces lying in planes paralleling said gasket bearingsurface; a gasket of resilient material between said gasket bearingsurface and said frame supporting the weight of the cathode assembly; adrip rim around the lower outer edge of said frame outside and extendingdownwardly of said plate, protecting said plate against anodicelectrolysis in case of leakage of electrolyte past said gasket; asecond gasket between said frame and said plate and tension meanscompressing said second gasket between said frame and said plate; saidslab and plate being protected against anodic electrolysis by a layer ofimpervious electrically non-conducting pressure-plastic materialextending around and between the lower ends of said anodic electrodes tosaid frame and making a sealing bond therewith.

2. In an electrolytic alkali chlorine cell comprising a cathode assemblyincluding a foraminous structure and cathodic electrodes housed in anupright liquid-retaining wall provided with a normally horizontal flatgasket bearing surface all around its lower edge and an anode assemblycooperative with said cathode assembly including upright anodicelectrodes having their lower ends embedded in a slab of low meltingmetal;

the improved support for said cathode and anode assemblies and bottomclosure for said retaining wall comprising a fiat metal plate extendingbeneath said retaining wall completely across from side to side thereofand conductively aflixed to said slab; a flat, four-sided open frame ofimpervious, electrically nonconducting material intervening between saidplate and the cathode assembly, conforming with said gasket bearingsurface in plan View, and having upper and lower boundary surfaces lyingin planes paralleling said gasket bearing surface; a gasket of resilientmaterial between said gasket bearing surface and said frame supportingthe weight of the cathode assembly, said plate being mortised into thebottom of said frame, leaving said frame extending 5 outwardly anddownwardly of said plate to form a drip rim protecting said plateagainst anodic electrolysis in case of leakage of electrolyte past saidgasket; a second gasket between said frame and said plate; and tensionmeans compressing 10 said second gasket between the frame Vand theplate; said slab and plate being protected against anodic electrolysisby a layer of impervious electrically non-conducting pressure-plasticmaterial extending around and between the lower ends of said anodcelectrode to said frame and making a sealing bond therewith.

KENNETH E. STUART.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS

